I agree with this. I make it known when someone tries to slip in a stereotypical joke behind someone's back that I don't approve. It made tensions between myself and an ex-roommate a little rough, because he assumed because we were both white I would support his views..

I was at a diversity workshop (long story) and one particular student was arguing long and hard that he has to "use that language" to "communicate properly" with his constituents and the like. His argument was that because the rednecks he knows speak that way, he would be alienating them by not doing it. When it was suggested he disapprove of their behavior, he blatantly refused. And this was a supposed student leader on a college campus.